How can I use the photo analysis? How do I take a good photo?

This guide shows you how to use photo analysis in the YaraPlus mobile app to get a nitrogen recommendation for winter oilseed rape and winter wheat.

Photo analysis uses images of your crop canopy to estimate its nitrogen status and support quick fertilisation decisions directly in the app. For more details, see What is photo analysis?.

Before you start

• Fertiliser restrictions
  • The photo analysis doesn't take official fertiliser limits into account. Please make sure your fertiliser application complies with local regulations.

• Supported crops and timing
  • Winter oilseed rape: before winter dormancy (optional follow-up in spring); crop height 5-60 cm; row spacing ≤50 cm; leaf cover ≤80 % (≤80 kg N/ha)
  • Winter wheat: spring (BBCH 20-30); row spacing 12-30 cm; leaf cover ≤70 % (≤40 kg N/ha)
  • The app blocks images above these thresholds to avoid misleading results. If you need nitrogen guidance in cereals at later growth stages, you can use the Yara N-Tester.

• Technical requirements
  • You'll need the YaraPlus mobile app.
  • You'll need a stable internet connection to prepare the activity and load the result. An internet connection isn't required while taking photos.
  • Depending on the step, you'll be asked to allow location and camera/photos access.

• Crop and measurement conditions
  • The crop should be healthy and well supplied with all essential nutrients except nitrogen. Nitrogen should be the main limiting factor.
  • The crop should be largely free of weeds, as these can affect image quality and lead to misleading results.

• Method limitations
  • Photo analysis reflects the crop conditions at the time of measurement. It doesn't account for future soil nitrogen supply.
  • The calculation assumes that nitrogen is the main limiting factor. Deficiencies in other nutrients aren't accounted for and may affect the result.
  • If the canopy is too dense, the app may reject the images to avoid misleading results.

Quick start (5 steps)

1. Open YaraPlus > Activity > New activity > Photo analysis
2. Allow location and camera permissions
3. Take or upload five to ten representative photos
4. Enter the required crop data
5. View the result and, if needed, assign it to a field

Step-by-step

Follow the steps below to perform a photo analysis.

1. Prepare analysis
2. Take photos
3. Enter crop data
4. View and save the result
5. (Optional) Assign result to a field

1) Prepare analysis

1. Log in to the YaraPlus mobile app.
2. Tap Activity in the bottom bar.
3. Tap New activity, then select Photo analysis.
   • Alternatively, start the analysis directly from a field in the Photo analysis section on the field page. This will automatically assign the result to the field.
4. Allow location and camera access if prompted.
   • On some devices, you may need to enable location services in your mobile device settings before launching the analysis. Otherwise, even if you grant permission in the app, the location itself may remain disabled and you won't be able to continue.
5. Select your crop.

2) Take photos

For reliable results, take clear and representative photos across the field.

1. Walk a W-shaped path across the field and take five to ten representative photos.
2. Hold your mobile device 1.5 m above the crop and keep it parallel to the ground.
3. Keep at least two crop rows fully in frame.
4. Avoid shadows, boots, weeds, gaps, tramlines or other objects in the photo.
5. In strong sun, shade the spot you're photographing with your body.
6. Use only green, unrolled leaves.
7. Tap the shutter button to take a photo or the gallery icon to upload photos you've already taken.
8. When finished, tap Done (✓).

You can also upload suitable photos from your gallery.

Winter oilseed rape (example)

Winter wheat (example)

3) Enter crop data

1. Select your farm from the first dropdown.
2. Select the production goal.
3. Depending on the crop, enter the required crop data:
   • Winter oilseed rape
     • Measurement date: before winter/after winter
     • Mineralisation potential: low/medium/high
     • Yield expectation
     • If measured after winter, enter either:
       • Autumn N-uptake, or
       • if unknown, fraction of brown leaves (%)
   • Winter wheat
     • Variety: choose from the list. If your variety is missing, contact our support team.
     • Growth stage: select BBCH 20-30
     • Seeding date: early/normal/late
     • Common first N dressing: enter your usual nitrogen rate for the first application
4. Tap Results to view the outcome.

4) View and save the recommendation

1. Review the result.
2. Check the following values:
   • Winter oilseed rape
     • N-recommendation – suggested rate for the first N application (tillering)
     • Leaf cover (%) – used to evaluate crop density
   • Winter wheat
     • N-recommendation – total N for the season, can be split into two applications
     • N-uptake – used to evaluate growth and N-uptake
     • Fresh matter weight – estimated from crop height and leaf cover to calculate nitrogen needs
3. Tap See all data entered to review the inputs used for the recommendation.
4. If needed, tap the bin icon (top right) to delete the recommendation.

Completed photo analyses are saved under Activity > Photo analysis.

(Optional) Assign result to a field

1. Open the result and tap Assign field.
2. Select the farm.
3. Select your field from the list (or Add field).
4. Tap Next to confirm.

Troubleshooting

• Fewer than five photos: add more photos across the field.
• Image too dense (leaf cover limit): measure earlier in the growth stage or choose a sparser area where the soil is still visible.
• Shadows or objects in frame: retake the photos with even lighting and avoid shadows, boots, weeds, gaps or tramlines.
• Permissions denied: enable camera and location access in your mobile device settings, then restart the analysis.
• Unsupported crop or timing: use photo analysis only for supported crops and early growth stages when the soil is still visible. Once the canopy closes, the analysis may be blocked or less accurate. For applications in cereals at BBCH stage 31 onwards, use the Yara N-Tester.

What's next?

Use your result to:

• Create variable-rate application maps
• Plan fertilisation for the season
• Browse the Yara fertiliser catalogue

Learn more

How the recommendations are calculated